Ink-jet print method and apparatus, color filter, display device, and apparatus having display device

ABSTRACT

It is an object of the present invention to provide an ink-jet print method which can uniformly distribute inks within each pixel array when a color filter is to be colored in a plurality of scanning operations. In order to achieve this object, there is provided an ink-jet print method of coloring each pixel array on a substrate by using an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to color one line for every scanning operation, including discharging the inks discharged in the plurality of scanning operations such that the inks are arranged at equal intervals within each pixel array.

BACKGROUND OF THE INVENTION

The present invention relates to an ink-jet print method and apparatusfor performing a print operation by discharging an ink from an ink-jethead onto a recording member, a color filter, a display device, and anapparatus having the display device.

With recent advances in personal computers, especially portable personalcomputers, the demand tends to arise for liquid crystal displays,especially color liquid crystal displays. However, in order to furtherpopularize the use of liquid crystal displays, a reduction in cost mustbe achieved. Especially, it is required to reduce the cost of a colorfilter which occupies a large proportion of the total cost. Variousmethods have been tried to satisfy the required characteristics of colorfilters while meeting the above requirements. However, any methodcapable of satisfying all the requirements has not been established. Therespective methods will be described below.

The first method is a pigment dispersion method. In this method, apigment-dispersed photosensitive resin layer is formed on a substrateand patterned into a single-color pattern. This process is repeatedthree times to obtain R, G, and B color filter layers.

The second method is a dyeing method. In the dyeing method, awater-soluble polymer material as a dyeable material is applied onto aglass substrate, and the coating is patterned into a desired shape by aphotolithographic process. The obtained pattern is dipped in a dye bathto obtain a colored pattern. This process is repeated three times toform R, G, and B color filter layers.

The third method is an electrodeposition method. In this method, atransparent electrode is patterned on a substrate, and the resultantstructure is dipped in an electrodeposition coating fluid containing apigment, a resin, an electrolyte, and the like to be colored in thefirst color by electrodeposition. This process is repeated three timesto form R, G, and B color filter layers. Finally, these layers arecalcined.

The fourth method is a print method. In this method, a pigment isdispersed in a thermosetting resin, a print operation is performed threetimes to form R, G, and B coatings separately, and the resins arethermoset, thereby forming colored layers. In either of the abovemethods, a protective layer is generally formed on the colored layers.

The point common to these methods is that the same process must berepeated three times to obtain layers colored in three colors, i.e., R,G, and B. This causes an increase in cost. In addition, as the number ofprocesses increases, the yield decreases. In the electrodepositionmethod, limitations are imposed on pattern shapes which can be formed.For this reason, with the existing techniques, it is difficult to applythis method to TFTs. In the print method, a pattern with a fine pitch isdifficult to form because of poor resolution and poor evenness.

In order to eliminate these drawbacks, methods of manufacturing colorfilters by an ink-jet system are disclosed in Japanese Patent Laid-OpenNos. 59-75205, 63-235901, and 1-217320. In these methods, inkscontaining coloring agents of three colors, i.e., R (red), G (green),and B (blue), are sprayed on a transparent substrate by an ink-jetsystem, and the respective inks are dried to form colored imageportions. In such an ink-jet system, R, G, and B pixels can be formed atonce, allowing great simplification of the manufacturing process and agreat reduction in cost.

When a color filter is to be manufactured by such an ink-jet system, anink may be discharged onto each pixel to color each pixel portion whilean ink-jet head having a plurality of ink discharging nozzles is scannedover a color filter substrate. In this case, however, since the amountsof ink discharged from a plurality of ink discharging nozzles slightlyvary, if one pixel array is colored by one nozzle, adjacent pixel arraysare colored by nozzles whose ink discharging amounts differ from eachother. It is known, therefore, that color irregularity occurs betweenthe pixel arrays. To reduce such color irregularity, a method ofperforming a scanning operation a plurality of times, and coloring pixelarrays by using different nozzles in the respective scanning operationshas been proposed. In this method of coloring each pixel array byperforming a scanning operation a plurality of times, however, inksdischarged in the respective scanning operations may overlap at someportions in each pixel array, resulting in an insufficient effect ofreducing the color irregularity, unless the manner of distributing inksin the respective scanning operations is studied.

SUMMARY OF THE INVENTION

The present invention has therefore been made in consideration of theabove problems, and has as its object to provide an ink-jet print methodand apparatus which can uniformly distribute inks within each line whenthe each line is to be printed in a plurality of scanning operations.

It is another object of the present invention to provide a color filtermanufactured by the above print method and apparatus, a display deviceusing the color filter, and an apparatus having the display device.

In order to solve the above problems and achieve the above objects, anink-jet print method according to the present invention is characterizedby the following process.

There is provided an ink-jet print method for printing lines on arecording member, in which each line is printed on a recording member bya plurality of scanning operations of an ink-jet head having a pluralityof ink discharging nozzles while changing the ink discharging nozzleused to print the each line for every scanning operation, comprisingdischarging the inks discharged in the plurality of scanning operationssuch that the inks are arranged at equal intervals within the each line.

An ink-jet print apparatus according to the present invention ischaracterized by the following arrangement.

There is provided an ink-jet print apparatus for printing lines on arecording member, in which each line is printed on a recording member bya plurality of scanning operations of an ink-jet head having a pluralityof ink discharging nozzles while changing the ink discharging nozzleused to print the each line for every scanning operation, comprisingscanning means for scanning the ink-jet head relative to the recordingmember, and control means for controlling an operation of the scanningmeans and an ink discharging timing of the ink-jet head such that theinks discharged in the plurality of scanning operations are arranged atequal intervals within the each line.

A color filter according to the present invention is characterized bythe following arrangement.

There is provided a color filter manufactured by coloring each pixelarray on a substrate by a plurality of scanning operations of an ink-jethead having a plurality of ink discharging nozzles while changing theink discharging nozzle used to print the each pixel array for everyscanning operation, wherein the color filter is manufactured bydischarging the inks discharged in the plurality of scanning operationssuch that the inks are arranged at equal intervals within the each line.

A display device according to the present invention is characterized bythe following arrangement.

There is provided a display device including a color filter manufacturedby coloring each pixel array on a substrate by a plurality of scanningoperations of an ink-jet head having a plurality of ink dischargingnozzles while changing the ink discharging nozzle used to print the eachpixel array for every scanning operation, integrally comprising thecolor filter manufactured by discharging the inks discharged in theplurality of scanning operations such that the inks are arranged atequal intervals within the each line, and light amount changing meansfor changing a light amount.

An apparatus including a display device according to the presentinvention is characterized by the following arrangement.

There is provided an apparatus including a display device including acolor filter manufactured by coloring each pixel array on a substrate bya plurality of scanning operations of an ink-jet head having a pluralityof ink discharging nozzles while changing the ink discharging nozzleused to print the each pixel array for every scanning operation,comprising the display device integrally including the color filtermanufactured by discharging the inks discharged in the plurality ofscanning operations such that the inks are arranged at equal intervalswithin the each line and light amount changing means for changing alight amount, and image signal supply means for supplying an imagesignal to the display device.

Other objects and advantages besides those discussed above shall beapparent to those skilled in the art from the description of a preferredembodiment of the invention which follows. In the description, referenceis made to accompanying drawings, which form a part hereof, and whichillustrate an example of the invention. Such example, however, is notexhaustive of the various embodiments of the invention, and thereforereference is made to the claims which follow the description fordetermining the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the schematic structure of a colorfilter manufacturing apparatus according to an embodiment of the presentinvention;

FIG. 2 is a block diagram showing the arrangement of a control unit forcontrolling the operation of the color filter manufacturing apparatus;

FIG. 3 is a perspective view showing the structure of an ink-jet headused for a color filter manufacturing apparatus;

FIG. 4 is a timing chart showing the waveforms of voltages applied tothe heaters of the ink-jet head;

FIGS. 5A to 5F are sectional views showing the process of manufacturinga color filter;

FIG. 6 is a sectional view showing the basic structure of a color liquidcrystal display device incorporating a color filter according to anembodiment of the present invention;

FIG. 7 is a block diagram showing an information processing apparatususing the liquid crystal display device;

FIG. 8 is a perspective view showing the information processingapparatus using the liquid crystal display device;

FIG. 9 is a perspective view showing the information processingapparatus using the liquid crystal display device;

FIG. 10 is a view for explaining a method of correcting the differencesbetween the amounts of ink discharged from the respective nozzles;

FIG. 11 is a graph for explaining the method of correcting thedifferences between the amounts of ink discharged from the respectivenozzles;

FIG. 12 is a view for explaining the method of correcting thedifferences between the amounts of ink discharged from the respectivenozzles;

FIG. 13 is a view for explaining a method of changing an ink dischargingdensity;

FIG. 14 is a view for explaining the method of changing an inkdischarging density;

FIG. 15 is a view for explaining the method of changing an inkdischarging density;

FIG. 16 is a perspective view showing the inner structure of a headmount;

FIG. 17 is a plan view of the head mount in FIG. 16;

FIG. 18 is a plan view showing the structure of an adjusting device foradjusting a head unit;

FIG. 19 is a side view showing the structure in FIG. 18 when viewed fromthe right side;

FIG. 20 is a flow chart showing an overall procedure for adjusting thehead unit;

FIG. 21 is a view showing printed patterns used for adjusting the anglesand relative positions of heads;

FIG. 22 is a flow chart showing a procedure for detecting variations inthe amounts of ink discharged from the respective nozzles of the heads;

FIG. 23 is a view showing printed patterns used for detecting variationsin the amounts of ink discharged from the heads;

FIG. 24 is a graph showing the relationship between the densities of inkdots and the amounts of ink discharged;

FIG. 25 is a flow chart showing a procedure for obtaining bit correctioninformation;

FIG. 26 is a view showing how inks overlap;

FIG. 27 is a view showing how inks spread when they overlap;

FIG. 28 is a view showing a state in which inks are discharged at equalintervals;

FIG. 29 is a view showing the concept of a color filter coloring methodaccording to the embodiment; and

FIG. 30 is a view showing a method of verifying whether a manufacturedcolor filter has been manufactured by the method of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will be described indetail below with reference to the accompanying drawings.

FIG. 1 is a schematic view showing the structure of a color filtermanufacturing apparatus according to an embodiment of the presentinvention.

Referring to FIG. 1, reference numeral 51 denotes an apparatus base; 52,an X-Y-θ stage disposed on the apparatus base 51; 53, a color filtersubstrate set on the X-Y-θ stage 52; 54, color filters formed on thecolor filter substrate 53; 55, a head unit including R (red), G (green),and B (blue) ink-jet heads for coloring the color filters 54 and a headmount 55 a supporting these heads; 58, a controller for controlling theoverall operation of a color filter manufacturing apparatus 90; 59, ateaching pendant (personal computer) as the display unit of thecontroller; and 60, a keyboard as the operation unit of the teachingpendant 59.

FIG. 2 is a block diagram showing the arrangement of the controller ofthe color filter manufacturing apparatus 90. The teaching pendant 59serves as the input/output means of the controller 58. Reference numeral62 denotes a display unit for displaying how a manufacturing processprogresses, information indicating the presence/absence of a headabnormality, and the like. The keyboard 60 designates an operation ofthe color filter manufacturing apparatus 90 and the like.

The controller 58 controls the overall operation of the color filtermanufacturing apparatus 90. Reference numeral 65 denotes an interfacefor exchanging data with the teaching pendant 59; 66, a CPU forcontrolling the color filter manufacturing apparatus 90; 67, a ROMstoring control programs for operating the CPU 66; 68, a RAM for storingproduction information and the like; 70, a discharge control unit forcontrolling discharging of an ink into each pixel of a color filter; and71, a stage control unit for controlling the operation of the X-Y-θstage 52 of the color filter manufacturing apparatus 90. The colorfilter manufacturing apparatus 90 is connected to the controller 58 andoperates in accordance with instructions therefrom.

FIG. 3 shows the structure of an ink-jet head IJH used in the colorfilter manufacturing apparatus 90. Referring to FIG. 1, in the head unit55, three ink-jet heads IJH are arranged in correspondence with threecolors, i.e., R, G, and B. Since these three heads have the samestructure, FIG. 3 shows the structure of one of the three heads as arepresentative.

Referring to FIG. 3, the ink-jet head IJH mainly comprises a heaterboard 104 as a board on which a plurality of heaters 102 for heating anink are formed, and a ceiling plate 106 mounted on the heater board 104.A plurality of discharging openings 108 are formed in the ceiling plate106. Tunnel-like fluid passages 110 communicating with the dischargingopenings 108 are formed therebehind. The respective fluid passages 110are isolated from the adjacent fluid passages via partition walls 112.The respective fluid passages 110 are commonly connected to one inkchamber 114 at the rear side of the fluid passages. An ink is suppliedto the ink chamber 114 via an ink inlet 116. This ink is supplied fromthe ink chamber 114 to each fluid passage 110.

The heater board 104 and the ceiling plate 106 are positioned such thatthe position of each heater 102 coincides with that of a correspondingfluid passage 110, and are assembled into the state shown in FIG. 3.Although FIG. 3 shows only two heaters 102, the heater 102 is arrangedin correspondence with each fluid passage 110. When a predetermineddriving signal is supplied to the heater 102 in the assembled stateshown in FIG. 3, an ink above the heater 102 is boiled to produce abubble, and the ink is pushed and discharged from the dischargingopening 108 upon volume expansion of the ink. Therefore, the size of abubble can be adjusted by controlling a driving pulse applied to theheater 102, e.g., controlling the magnitude of power. That is, thevolume of the ink discharged from each discharging opening can bearbitrarily controlled.

FIG. 4 is a timing chart for explaining a method of controlling theamount of ink discharged by changing power supplied to each heater inthis manner.

In this embodiment, two types of constant-voltage pulses are applied toeach heater 102 to adjust the amount of ink discharged. The two pulsesare a preheat pulse and a main heat pulse (to be simply referred to as aheat pulse hereinafter), as shown in FIG. 4. The preheat pulse is apulse for heating an ink to a predetermined temperature before the inkis actually discharged. The pulse width of this pulse is set to besmaller than a minimum pulse width t5 required to discharge the ink.Therefore, the ink is not discharged by this preheat pulse. The preheatpulse is applied to each heater 102 to increase the initial temperatureof the ink to a predetermined temperature in advance so as to alwaysmake the amount of ink discharged constant when a constant heat pulse isapplied to the heater 102 afterward. In contrast to this, thetemperature of the ink may be adjusted in advance by adjusting the widthof a preheat pulse. In this case, for the same heat pulse, the amount ofink discharged can be changed. In addition, by heating ink beforeapplication of a heat pulse, the start time required to discharge theink upon application of the heat pulse can be shortened to improve theresponsibility.

The heat pulse is a pulse for actually discharging the ink. The pulsewidth of the heat pulse is set to be larger than the minimum pulse widtht5 required to discharge the ink. Energy generated by each heater 102 isproportional to the width (application time) of a heat pulse. Therefore,variations in the characteristics of the heaters 102 can be adjusted byadjusting the width of each heat pulse.

Note that the amount of ink discharged can also be adjusted by adjustingthe interval between a preheat pulse and a heat pulse to control thedispersed state of heat upon application of the preheat pulse.

As is apparent from the above description, the amount of ink dischargedcan be controlled both by adjusting the application time of a preheatpulse and by adjusting the interval between application of a preheatpulse and that of a heat pulse. Therefore, by adjusting the applicationtime of a preheat pulse or the interval between application of a preheatpulse and that of a heat pulse as needed, the amount of ink dischargedor the responsibility of discharging of the ink with respect to anapplied pulse can be arbitrarily adjusted.

Such adjustment of the amount of ink discharged will be described indetail next.

Assume that an ink is discharged in different amounts from dischargingopenings (nozzles) 108 a, 108 b, and 108 c upon application of the samevoltage pulse, as shown in FIG. 4. More specifically, assume that when avoltage having a predetermined pulse width is applied at a predeterminedtemperature, the amount of ink discharged from the nozzle 108 a is 36 pl(pico-liters); the amount of ink discharged from the nozzle 108 b, 40pl; and the amount of ink discharged from the nozzle 108 c, 40 pl, andthe resistance of heaters 102 a and 102 b corresponding to the nozzles108 a and 108 b is 200 Ω, and the resistance of a heater 102 ccorresponding to the nozzle 108 c is 210 Ω. Assume that the amounts ofink discharged from the nozzles 108 a, 108 b, and 108 c are to beadjusted to 40 pl.

The widths of a preheat pulse and a heat pulse may be adjusted to adjustthe amounts of ink discharged from the nozzles 108 a, 108 b, and 108 cto the same amount. Various combinations of the widths of preheat pulsesand heat pulses are conceivable. In this case, the amounts of energygenerated by heat pulses are made equal for the three nozzles, and theamounts of ink discharged are adjusted by adjusting the widths ofpreheat pulses.

Since the heaters 102 a and 102 b for the nozzles 108 a and 108 b havethe same resistance, i.e., 200 Ω, the amounts of energy generated byheat pulses can be made equal by applying voltage pulses having the samewidth to the heaters 102 a and 102 b. In this case, the width of eachvoltage pulse is set to be t3 which is larger than the width t5. An inkis discharged in different amounts, i.e., 36 pl and 40 pl, from thenozzles 108 a and 108 b upon application of identical heat pulses. Inorder to increase the amount of ink discharged from the nozzle 108 a, apreheat pulse having a width t2 larger than a width t1 of a preheatpulse applied to the heater 102 b is applied to the heater 102 a. Withthis operation, the amounts of ink discharged from the heaters 108 a and108 b can be adjusted to 40 pl.

The heater 102 c for the nozzle 108 c has a resistance of 210 Ω, whichis higher than the resistance of the two remaining heaters 102 a and 102b. For this reason, in order to cause the heater 102 c to generate thesame amount of energy as that generated by the two remaining heaters,the width of a heat pulse must be set to be larger than that of theabove heat pulse. In this case, therefore, the width of the heat pulseis set to be t4 which is larger than the width t3. Since the amounts ofink discharged from the nozzles 108 b and 108 c upon application of apredetermined pulse are the same, the width of a preheat pulse requiredis equal to that of a preheat pulse applied to the heater 102 b. Thatis, a preheat pulse having the width t1 is applied to the heater 102 c.

In the above manner, the same amount of ink can be discharged from thenozzles 108 a, 108 b, and 108 c which discharge an ink in differentamounts upon application of a predetermined pulse. In addition, theamounts of ink discharged may be intentionally made to differ from eachother. Note that preheat pulses are used to reduce variations in thedischarging operation of each nozzle.

FIGS. 5A to SF show an example of the process of manufacturing a colorfilter.

In this embodiment, a glass substrate is generally used as a substrate1. However, a substrate other than a glass substrate can be used as longas it has characteristics required for a liquid crystal color filter,e.g., good transparency and high mechanical strength.

FIG. 5A shows the glass substrate 1 having a black matrix 2 constitutedby light-transmitting portions 7 and light-shielding portions. First ofall, the glass substrate 1, on which the black matrix 2 is formed, iscoated with a resin composition which can be cured upon irradiation oflight or irradiation of light and heating, and has ink receptivity. Theresultant structure is prebaked, as needed, to form a resin layer 3′(FIG. 5B). The resin layer 3′ can be formed by a coating method such asspin coating, roller coating, bar coating, spraying, or dipping.However, the present invention is not limited to any specific coatingmethod.

Subsequently, pattern exposure is performed in advance onto resin layerportions light-shielded by the black matrix 2 by using a photomask 4′ tocure the exposed portions of the resin layer so as to form portions 5′(non-colored portions) which do not absorb an ink (FIG. 5C). Thereafter,the resin layer is colored in R, G, and B at once by using the ink-jetheads (FIG. 5D), and the inks are dried, as needed.

As the photomask 4′ used when pattern exposure is performed, a maskhaving opening portions for curing the portions light-shielded by theblack matrix is used. In this case, in order to prevent a color omissionof the color material at a portion in contact with the black matrix, arelatively large amount of ink must be discharged. For this reason, amask having opening portions each having a size smaller than the widthof each light-shielding portion of the black matrix is preferably used.

As an ink to be used for a coloring operation, both dye and pigment inkscan be used, and both liquid and solid inks can be used.

As a curable resin composition to be used in the present invention, anyresin composition which has ink receptivity and can be cured by at leastone of the following treatments: irradiation of light and a combinationof irradiation of light and heating, can be used. As resins, acrylicresin, epoxy resin, and silicone resin are available. As cellulosederivatives, hydroxypropyl cellulose, hydroxy ethyl cellulose, methylcellulose, carboxymethyl cellulose are available, and modified materialsthereof are also available.

Optical initiators (crosslinkers) can also be used to crosslink theseresins by irradiation of light or irradiation of light and heating. Asoptical initiators, dichromate, a bis-azide compound, a radical-basedinitiator, a cation-based initiator, an anion-based initiator, and thelike can be used. Mixtures of these optical initiators and combinationsof the initiators and sensitizers can also be used. In addition, anoptical acid generating agent such as onium salt can be used as acrosslinker. In order to make a crosslinking reaction further progress,a heat treatment may be performed after irradiation of light.

Resin layers containing these compositions have excellent heatresistance, excellent water resistance, and the like, and aresufficiently resistant to high temperatures and cleaning in thesubsequent steps.

As an ink-jet system used in the present invention, a bubble-jet typeusing an electrothermal converter as an energy generating element, apiezoelectric jet type using a piezoelectric element, or the like can beused. A coloring area and coloring pattern can be arbitrarily set.

This embodiment exemplifies the structure in which the black matrix isformed on the substrate. However, after a curable resin compositionlayer is formed or after coloring is performed, a black matrix may beformed on the resin layer without posing any problem. That is, the formof a black matrix is not limited to that in this embodiment. As a methodof forming a black matrix, a method of forming a thin metal film on asubstrate by sputtering or deposition, and patterning the film by aphotolithographic process is preferably used. However, the presentinvention is not limited to this.

Subsequently, the curable resin composition is cured by performing onlyone of the following treatments: irradiation of light, a heat treatment,and a combination of irradiation of light and a heat treatment (FIG.5E), and a protective layer 8 is formed, as needed (FIG. 5F). Note thatreference symbol hν denotes the intensity of light. When a heattreatment is to be performed, heat is applied instead of hν. Theprotective layer 8 can be made of a second resin composition of aphoto-setting type, thermosetting type, or photo-setting/thermosettingtype. The resultant layer needs to have transparency upon formation of acolor filter and be sufficiently resistant to the subsequent processessuch as an ITO formation process and an aligning film formation process.

Although the resin composition is formed on the substrate in thisembodiment, inks may be directly discharged onto the substrate in thefollowing manner.

The ink-jet system is used to discharge R, G, and B inks onto thesubstrate to fill the light-transmitting portions of a black matrixwhich forms light-shielding portions. These R, G, and B patterns may beformed in the form of a so-called casting. Inks of the respective colorsare preferably printed within the range in which they do not overlap onthe black matrix.

As an ink to be used, both dye and pigment inks can be used as long asthey can be set upon application of energy such as light and heat, andboth liquid and solid inks can be used. The ink must contain aphoto-setting component, a thermosetting component, orphoto-setting/thermosetting component. As such components, variouscommercially available resins and curing agents can be used, and are notspecifically limited as long as they do not cause problems such asretention in the ink. More specifically, acrylic resin, epoxy resin,melamine resin, and the like can be suitably used.

FIG. 6 is a sectional view showing the basic structure of a color liquidcrystal display device 30 incorporating the above color filter.

In general, a color liquid crystal panel is formed by joining the colorfilter substrate 1 to a counter substrate 21 and sealing a liquidcrystal compound 18 therebetween. TFTs (Thin Film Transistors) (notshown) and transparent pixel electrodes 20 are formed on the innersurface of one substrate 21 of the liquid crystal panel in a matrixform. A color filter 54 is placed on the inner surface of the othersubstrate 1 such that the R, G, and B coloring materials are positionedto oppose the pixel electrodes. A transparent counter electrode (commonelectrode) 16 is formed on the entire surface of the color filter 54.The black matrix 2 is generally formed on the color filter substrate 1side. Aligning films 19 are formed within the planes of the twosubstrates. By performing a rubbing process for the aligning films 19,the liquid crystal molecules can be aligned in a predetermineddirection. Polarizing plates 11 and 22 are bonded to the outer surfaceof the respective glass substrates. The liquid crystal compound 18 isfilled in the gap (about 2 to 5 μm) between these glass substrates. As abacklight, a combination of a fluorescent lamp (not shown) and ascattering plate (not shown) is generally used. A display operation isperformed by causing the liquid crystal compound to serve as an opticalshutter for changing the transmittance for light emitted from thebacklight.

A case wherein the above liquid crystal display device is applied to aninformation processing apparatus will be described below with referenceto FIGS. 7 to 9.

FIG. 7 is a block diagram showing the schematic arrangement of aninformation processing apparatus serving as a wordprocessor, a personalcomputer, a facsimile apparatus, and a copying machine, to which theabove liquid crystal display device is applied.

Referring to FIG. 7, reference numeral 1801 denotes a control unit forcontrolling the overall apparatus. The control unit 1801 includes a CPUsuch as a microprocessor and various I/O ports, and performs control byoutputting/inputting control signals, data signals, and the like to/fromthe respective units. Reference numeral 1802 denotes a display unit fordisplaying various menus, document information, and image data read byan image reader 1807, and the like on the display screen; 1803, atransparent, pressure-sensitive touch panel mounted on the display unit1802. By pressing the surface of the touch panel 1803 with a finger ofthe user or the like, an item input operation, a coordinate positioninput operation, or the like can be performed on the display unit 1802.

Reference numeral 1804 denotes an FM (Frequency Modulation) sound sourceunit for storing music information, created by a music editor or thelike, in a memory unit 1810 or an external memory unit 1812 as digitaldata, and reading out the information from such a memory, therebyperforming FM modulation of the information. An electrical signal fromthe FM sound source unit 1804 is converted into an audible sound by aspeaker unit 1805. A printer unit 1806 is used as an output terminal forthe wordprocessor, the personal computer, the facsimile apparatus, andthe copying machine.

Reference numeral 1807 denotes an image reader unit forphotoelectrically reading original data. The image reader unit 1807 isarranged midway along the original convey passage and designed to readoriginals for facsimile and copy operations and other various originals.

Reference numeral 1808 denotes a transmission/reception unit for thefacsimile (FAX) apparatus. The transmission/reception unit 1808transmits original data read by the image reader unit 1807 by facsimile,and receives and decodes a sent facsimile signal. Thetransmission/reception unit 1808 has an interface function for externalunits. Reference numeral 1809 denotes a telephone unit having a generaltelephone function and various telephone functions such as an answeringfunction.

Reference numeral 1810 denotes a memory unit including a ROM for storingsystem programs, manager programs, application programs, fonts, anddictionaries, a RAM for storing an application program loaded from theexternal memory unit 1812 and document information, a video RAM, and thelike.

Reference numeral 1811 denotes a keyboard unit for inputting documentinformation and various commands.

Reference numeral 1812 denotes an external memory unit using a floppydisk, a hard disk, and the like. The external memory unit 1812 serves tostore document information, music and speech information, applicationprograms of the user, and the like.

FIG. 8 is a perspective view of the information processing apparatus inFIG. 7.

Referring to FIG. 8, reference numeral 1901 denotes a flat panel displayusing the above liquid crystal display device, which displays variousmenus, graphic pattern information, document information, and the like.A coordinate input or item designation input operation can be performedon the flat panel display 1901 by pressing the surface of the touchpanel 1803 with a finger of the user or the like. Reference numeral 1902denotes a handset used when the apparatus is used as a telephone set. Akeyboard 1903 is detachably connected to the main body via a cord and isused to perform various document functions and input various data. Thiskeyboard 1903 has various function keys 1904. Reference numeral 1905denotes an insertion port through which a floppy disk is inserted intothe external memory unit 1812.

Reference numeral 1906 denotes an original table on which an original tobe read by the image reader unit 1807 is placed. The read original isdischarged from the rear portion of the apparatus. In a facsimilereceiving operation or the like, received data is printed out by anink-jet printer 1907.

When the above information processing apparatus is to serve as apersonal computer or a wordprocessor, various kinds of information inputthrough the keyboard unit 1811 are processed by the control unit 1801 inaccordance with a predetermined program, and the resultant informationis output, as an image, to the printer unit 1806.

When the information processing apparatus is to serve as the receiver ofthe facsimile apparatus, facsimile information input through thetransmission/reception unit 1808 via a communication line is subjectedto reception processing in the control unit 1801 in accordance with apredetermined program, and the resultant information is output, as areceived image, to the printer unit 1806.

When the information processing apparatus is to serve as the copyingmachine, an original is read by the image reader unit 1807, and the readoriginal data is output, as an image to be copied, to the printer unit1806 via the control unit 1801. Note that when the informationprocessing apparatus is to serve as the receiver of the facsimileapparatus, original data read by the image reader unit 1807 is subjectedto transmission processing in the control unit 1801 in accordance with apredetermined program, and the resultant data is transmitted to acommunication line via the transmission/reception unit 1808.

Note that the above information processing apparatus may be designed asan integrated apparatus incorporating an ink-jet printer in the mainbody, as shown in FIG. 9. In this case, the portability of the apparatuscan be improved. The same reference numerals in FIG. 9 denote partshaving the same functions as those in FIG. 8.

Two typical methods of reducing density irregularity in the respectivepixels of a color filter will be described next.

FIGS. 10 to 12 show a method (to be referred to as bit correctionhereinafter) of correcting the differences between the amounts of inkdischarged from the respective nozzles of the ink-jet head IJH having aplurality of ink discharging nozzles.

First of all, as shown in FIG. 10, inks are discharged from, forexample, three nozzles 1, 2, and 3 of the ink-jet head IJH onto apredetermined substrate P. The sizes or densities of ink dots formed onthe substrate P by the inks discharged from the respective nozzles aremeasured to measure the amounts of ink discharged from the respectivenozzles. In this case, the width of a heat pulse (see FIG. 4) to beapplied to each nozzle is kept constant, whereas the width of a preheatpulse (see FIG. 4) is changed, as described above. With this setting,curves, like those shown in FIG. 11, exhibiting relationships betweenthe preheat pulse widths (represented by the heat time in FIG. 11) andink discharging amounts can be obtained. As is obvious from FIG. 11, thewidths of preheat pulses to be applied to the nozzles 1, 2, and 3 are1.0 μs, 0.5 μs, and 0.75 μs, respectively. All the amounts of inkdischarged from the respective nozzles can therefore be set to 20 ng asshown in FIG. 12 by applying the preheat pulses having these widths tothe heaters of the respective nozzles. Correcting the amounts of inkdischarged from the respective nozzles will be called bit correction. Inthis embodiment, for example, the width of a preheat pulse is changed infour levels to realize a correction width of about 30%. The correctionresolution is 2 to 3%.

FIGS. 13 to 15 show a method (to be referred to as shading correctionhereinafter) of correcting density irregularity in the scanningdirection of the ink-jet head by adjusting the density of an inkdischarged from each ink discharging nozzle.

Assume that the amounts of ink discharged from the nozzles 1 and 2 ofthe ink-jet head are −10% and +20%, respectively, relative to the amountof ink discharged from the nozzle 3, as shown in FIG. 13. In this case,while the ink-jet head IJH is scanned, a heat pulse is applied to theheater of the nozzle 1 once for every nine reference clocks, a heatpulse is applied to the heater of the nozzle 2 once for every 12reference clocks, and a heat pulse is applied to the heater of thenozzle 3 once for every 10 reference clocks, as shown in FIG. 14. Withthis operation, inks are discharged from the respective nozzlesdifferent numbers of times in the scanning direction so the inkdensities of the pixels of the color filter in the scanning directioncan be made uniform, as shown in FIG. 15, thereby preventing densityirregularity in the respective pixels. Correcting the ink dischargingdensities in the scanning direction in this manner is called shadingcorrection.

In this embodiment, the head unit 55 is detachably mounted on the colorfilter manufacturing apparatus 90 such that the pivot angle of the unitcan be adjusted within a horizontal plane, as described above. The R, G,and B ink-jet heads in the head unit 55 are adjusted by the adjustingdevice provided independently of the color filter manufacturingapparatus 90. The head unit 55 adjusted by this adjusting device ismounted on the color filter manufacturing apparatus 90, and only thepivot angle of the unit within a horizontal place is adjusted. With thisarrangement, when the head unit 55 is mounted on the color filtermanufacturing apparatus 90 and simple adjustment is performed, coloringof a color filter can be immediately started without performing otheradjusting operations. When the head unit 55 is adjusted by the separateadjusting device, dust can be prevented, as compared with a case inwhich the head is adjusted while being mounted on the color filtermanufacturing apparatus 90. In addition, since the color filtermanufacturing apparatus 90 need not be stopped for the adjustment of thehead, the availability of the apparatus can be improved.

Prior to a description of the adjusting device for adjusting the headunit 55, the structure of the head unit 55 will be described first.

The head unit 55 in this embodiment has a plurality of multi-nozzle typeink-jet heads, each having a plurality of nozzles, supported by themount head 55 a.

The mount head 55 a has a mechanism for simultaneously changing themounting angles of a plurality of heads, and a mechanism for separatelyadjusting the positions of the heads in the sub-scanning direction.

The pixels of a color filter are basically colored by the ink-jet methodin the following manner. First of all, multi-nozzle heads, each having aplurality of nozzles at a predetermined pitch, and more specifically,nozzles corresponding to the pixel pitch, are used to perform coloringin the main scanning direction. The heads or the substrate is then movedin the sub-scanning direction, and coloring in the main scanningdirection is repeated.

Since the nozzle pitch of each multi-nozzle type ink-jet head in thisembodiment is smaller than the pixel pitch, coloring is performed byusing every plurality of nozzles. If a pixel pitch does not coincidewith a multiple of the nozzle pitch, the angle of each ink-jet head ischanged from 90° with respect to the main scanning direction to matchwith the pixel pitch.

In this case, with a mechanism for simultaneously rotating a pluralityof heads having the same nozzle pitch and a mechanism for finelyadjusting the angle of each head, the pixel pitch and the pitch ofnozzles, of each ink-jet head, which are to be used can be efficientlymatched with each other.

In addition, with a mechanism for finely moving each ink-jet head in thesub-scanning direction, the nozzle positions of a plurality of heads canbe set to desired pixel positions of the color filter.

FIG. 16 is a perspective view showing the inner structure of the mounthead 55 a. FIG. 17 is a plan view of the mount head 55 a in FIG. 16.

Referring to FIGS. 16 and 17, reference numerals 204 a, 204 b, and 204 cdenote multi-nozzle type ink-jet heads. These three ink-jet heads, i.e.,the R (red) head 204 a, the G (green) head 204 b, and the B (blue) head204 c, can be normally mounted on the mount head 55 a. A plurality ofnozzles 205 (the nozzles are mounted on the lower surfaces of theink-jet heads and hence cannot be seen actually in FIG. 17, but areindicated by the solid lines for the sake of descriptive convenience)are arranged at the same pitch in the longitudinal direction of theheads. One end portion of each of the ink-jet heads 204 a, 204 b, and204 c is supported by a corresponding one of holders 208 a, 208 b, and208 c. These holders are supported to be pivotal about rotating shafts206 a, 206 b, and 206 c fixed to the mount head 55 a within a horizontalplane with respect to the mount head 55 a. The other end portion of eachof the ink-jet heads 204 a, 204 b, and 204 c is supported by acorresponding one of holders 210 a, 210 b, and 210 c. These holders aresupported to be pivotal about rotating shafts 212 a, 212 b, and 212 cwithin a horizontal plane with respect to a slide member 214. Therotating shafts 212 a, 212 b, and 212 c are eccentric shafts. Byrotating slot portions 212 al, 212 bl, and 212 cl (only the slot portion212 cl is not shown) at the head portions of the rotating shafts 212 a,212 b, and 212 c, the holders 210 a, 210 b, and 210 c can be finelymoved in the direction indicated by an arrow I with respect to the slidemember 214. With this structure, the pivot angles of the ink-jet heads204 a, 204 b, and 204 c can be finely adjusted independently of eachother. The slide member 214 is supported to be movable in the X and Ydirections with respect to the mount head 55 a, and is biased by aspring 216 in the direction indicated by an arrow A. A micrometer screw218 is set on the opposite side of the mount head 55 a to the spring216. By rotating the micrometer screw 218, the spring 216 is moved inthe X direction. With this operation, the three ink-jet heads 204 a, 204b, and 204 c can be simultaneously inclined by an arbitrary angle θ withrespect to the positions indicated by the dotted lines in FIG. 17 (theY-axis), thereby adjusting the inclinations of the heads with respect tothe scanning direction. By rotating the eccentric shafts 212 a, 212 b,and 212 c, the inclination angles of the respective heads can be finelyadjusted independently. In addition, compression springs 220 a, 220 b,and 220 c are arranged in the holders 210 a, 210 b, and 210 c to biasthe ink-jet heads 204 a, 204 b, and 204 c to the right in FIG. 17.Micrometer screws 222 a, 222 b, and 222 c are set on the holders 208 a,208 b, and 208 c to oppose the compression springs 220 a, 220 b, and 220c. By rotating these micrometer screws, the positions of the respectiveink-jet heads can be adjusted in the direction indicated by an arrow B(the sub-scanning direction).

If the mount head 55 a is set on the adjusting device such that the mainscanning direction X coincides with a straight line connecting therotating shafts 206 a, 206 b, and 206 c of the respective heads,adjustment is facilitated.

In actually adjusting the heads, the heads are simultaneously rotatedabout the head rotating shafts 206 a, 206 b, and 206 c to adjust theangle θ of the respective heads so as to match the pitch of desirednozzles (nozzles used for coloring) with a pixel pitch. In addition, theslight differences between the relative angles of the respective headsare adjusted by rotating the eccentric shafts 212 a, 212 b, and 212 c.In this case, each head is inclined by the angle θ that satisfiesb=na·cos θ (n is a positive integer) where a is the nozzle pitch (μm),and b is the pixel pitch (μm). Thereafter, the micrometer screws 222 a,222 b, and 222 c are adjusted to match the positions of the nozzles withthe positions of R, G, and B pixel patterns.

FIG. 18 is a plan view showing the structure of an adjusting device 300for adjusting the head unit 55. FIG. 19 is a side view of the adjustingdevice 300 in FIG. 18 when viewed from the right side.

Referring to FIGS. 18 and 19, an X slide guide 306 extending in the Xdirection is mounted on a base (not shown). A Y slide guide 308extending in the Y direction is supported on the X slide guide 306 to beslidable in the X direction. The Y slide guide 308 is slid/driven on theX slide guide 306 in the X direction by a driving mechanism (not shown).A table 304 is supported on the Y slide guide 308 to be slidable in theY direction. A glass substrate 302 to which inks are discharged for headadjustment is placed on the table 304. The glass substrate 304 isslid/driven on the Y slide guide 308 in the Y direction by a drivingmechanism (not shown). As a result, the table 304, i.e., the glasssubstrate 302, is moved/driven two-dimensionally in the X and Ydirections with respect to the base (not shown).

The head unit 55 is placed above the table 304 while being mounted on ahead support column 312 of the adjusting device 300, as shown in FIG.19. A line sensor camera 310 for reading ink dots printed on the glasssubstrate 302 is placed on a side of the head unit 55.

A restoring unit 314 is placed on an extended line of the X slide guide306. The restoring unit 314 restores the ink discharging nozzles of theink-jet heads 204 a, 204 b, and 204 c from discharge failures to normalstates by sucking inks from the nozzles.

A procedure for adjusting the head unit 55 by using the adjusting devicehaving the above structure will be described below.

FIG. 20 is a flow chart showing the overall procedure for adjusting thehead unit. The overall procedure for adjusting the head unit will bedescribed with reference to this flow chart of FIG. 20. The respectivesteps will be described in detail later.

First of all, the ink-jet head unit 55 incorporating a plurality ofheads each having undergone a screening test, precision adjustment, andthe like is mounted on the restoring unit 314 head support column 312 ofthe adjusting device 300 (step S1).

Subsequently, drive voltages to be applied to the respective headsincorporated in the head unit are adjusted (K value adjustment). In thisadjustment, a voltage V_(op) in FIG. 4 is gradually increased todischarge ink so as to set each drive voltage to a constant multiple ofa threshold voltage for starting a discharging operation. In thisembodiment, the drive voltages were set to about 24 V to 26 V (step S2)although they differ depending on the heads.

Aging is performed for a predetermined period of time to eliminate theinitial unstable region of discharging from each head. In this test,inks were discharged from all the nozzles 6×10⁶ times (step S3).

Inks are discharged from the heads 204 a, 204 b, and 204 c of the headunit 55 to print patterns, on the glass substrate 302, which are usedfor the angle and relative position adjustment of the respective heads(step S4). The patterns are read by a line sensor camera 310, and theangles and relative positions of the respective heads are adjusted onthe basis of data obtained from the read patterns (step S5).

Inks are discharged from the respective heads to print patterns, on theglass substrate 302, which are used to detect the amounts of inkdischarged from the respective nozzles of the heads, and the patternsare read by the line sensor camera 310 to detect the amounts of inkdischarged from the respective nozzles on the basis of the densities ofthe read patterns (step S6).

If there are differences between the amounts of ink discharged from therespective nozzles, data about the densities of the inks discharged fromthe respective nozzles, i.e., data for the above shading correction, isgenerated to equalize the densities of the patterns printed in units ofnozzles. Patterns are then printed after shading correction based on thegenerated shading correction data, and the density differences(corresponding to the total amounts of ink discharged per unit length inthe scanning direction) of the printed patterns are checked (step S7).

Changes in the amounts of ink discharged from the respective nozzleswith changes in the lengths of preheat pulses applied to the heaters ofthe respective nozzles (using the above bit correction method) aremeasured (step S8).

Data indicating the lengths of preheat pulses to be applied to theheaters of the respective nozzles so as to equalize the amounts of inkdischarged from the respective nozzles is generated on the basis of thedata about the amounts of ink discharged from the respective nozzles,obtained in step S6, and the data about changes in the amounts of inkdischarged with changes in the lengths of preheat pulses, obtained instep S8. Patterns are printed after shading correction and bitcorrection based on the shading correction data generated in step S7 andthe bit correction data generated in step S8, and the densitydifferences (corresponding to the total amounts of ink discharged perunit length in the scanning direction) of the printed patterns arechecked (step S9).

If there are density differences between the patterns printed in unitsof nozzles even after shading correction and bit correction in step S9,one pixel is colored by performing a scanning operation a plurality ofnumber of times (to be called a multi-pass method hereinafter), anddifferent nozzles are used for the respective scanning operations. When,for example, one pixel array is to be colored by three scanningoperations, the first nozzle is used for the first scanning operation;the second nozzle, for the second scanning operation; and the thirdnozzle, for the third scanning operation. In this manner, differentnozzles are used for the respective scanning operations. In this case, asimulation is performed to find which nozzles should be used in thefirst, second, and third scanning operations to minimize the densitydifferences between the respective pixel arrays. In step S10, thissimulation is performed to generate data indicating the specific ordinalnumbers of nozzles to be used in the respective scanning operations. Asmethods of adjusting the amounts of ink discharged, two types ofmethods, i.e., shading correction and bit correction, are described.However, it suffices if one of the methods is performed. In many cases,the amounts of ink discharged can be satisfactorily corrected by shadingcorrection alone. That is, bit correction is not essential (steps S8 andS9 in FIG. 20).

Finally, mass production data that specifies the specific nozzles to beused and the specific ink discharging patterns in actually coloring acolor filter is generated on the basis of the data obtained in steps S7to S10 (step S11). In addition, mass production data can be generatedwithout performing bit correction, as described above, with heat pulsesapplied to the heaters of the respective nozzles being made uniform.

Note that the above simulation calculation and control on headadjustment are performed by a control unit 330.

The head unit 55 is adjusted in the above manner.

A detailed operating procedure in each step in the flow chart of FIG. 20will be described next.

In step S4 in FIG. 20, first of all, the micrometer screw 218 of thehead unit 55 is rotated to incline the R, G, and B heads 204 a, 204 b,and 204 c such that the nozzle pitch almost coincides with the pixelpitch of the color filter. In this embodiment, for example, the pitch ofthe pixel arrays is 264 μm. The X slide guide 306 is then driven to movethe table 304 in the X direction, and the head unit 55 is scanned in theX direction relative to the glass substrate 302. Meanwhile, for example,ink dots are printed, five at a time, on the glass substrate 302 at apitch of 400 μm in the scanning direction by using the respectivenozzles of each of the heads 204 a, 204 b, and 204 c. FIG. 21 shows theresultant printed patterns.

Subsequently, the printed patterns are read by the line sensor camera310 while the Y slide guide 308 is driven to move the table 304 in the Ydirection, and the line sensor camera 310 is scanned in the Y directionrelative to the glass substrate 302. The read printed patterns aresubjected to image processing to obtain the center-of-gravity positionsof the respective ink dots. Straight lines I₁ to I₅ that almost passthrough the centers of gravity are obtained by least squaresapproximation. Angles θ1 to θ5 defined by the straight lines I₁ to I₅and the Y-axis are obtained. The averages of these angles are thenobtained as θa, θb, and θc defined by the heads 204 a, 204 b, and 204 cand the Y-axis. In addition, relative distances db and dc between thenozzles of the respective heads in the Y direction are obtained fromstraight lines passing through the centers of gravity of dots arrangedin the X direction.

In step S5, the eccentric shafts 212 a, 212 b, and 212 c for finelyadjusting the angles of the respective heads are rotated to perform fineadjustment such that the angles θa, θb, and θc obtained in step S4 areset to desired angles. In addition, the micrometer screws 222 a, 222 b,and 222 c for finely adjusting the respective heads in the sub-scanningdirection are rotated to finely adjust the positions of the respectiveheads such that the relative distances db and dc between the respectiveheads in the Y direction are set to desired distances. With the aboveoperations, the angle adjustment and position adjustment of therespective heads are complete.

FIG. 22 is a flow chart showing the detailed contents of a procedure formeasuring variations in the amounts of ink discharged from therespective nozzles (step S6) in the flow chart of FIG. 20.

First of all, inks are discharged from the nozzles of the respectiveheads while the head unit 55 is scanned in the X direction relative tothe glass substrate 302, thereby printing line patterns each having alength of about 50 mm, as shown in FIG. 23. In this case, preheat andheat pulses having the same patterns are applied to the heaters of therespective nozzles, and bit correction is performed at an intermediatepoint (bit correction value “8”) (step S12).

Subsequently, the densities of the respective line patterns printed instep S10 are measured while the line sensor camera 310 is scanned in theY direction relative to the glass substrate 302 (step S13).

The amounts of ink discharged from the respective nozzles are obtainedfrom the densities of the respective line patterns which are obtained instep S13 (step S14). With the above operation, data about variations inthe amounts of ink discharged from the respective nozzles can beobtained.

A method of obtaining the amounts of ink discharged from the densitiesof line patterns will be described in detail below.

First of all, the densities of printed line patterns like those in FIG.23 are measured by the line sensor camera 310. In this case, accordingto this embodiment, since each line pattern has a width of about 70 μm,the integral value of densities within the range of +40 μm from thecenter-of-gravity position of each line pattern in the Y direction ismeasured.

A calibration curve as a reference in measuring the amount of inkdischarged from an arbitrary nozzle of an ink-jet head per dischargingoperation under arbitrary conditions is obtained. The amount of inkdischarged from a nozzle per discharging operation generally indicatesthe amount of one ink droplet. However, since an ink may not become adroplet, the expression “the amount of ink discharged per dischargingoperation” is used instead of “the amount of one ink droplet”.

First of all, the amounts of ink discharged from at least two nozzlesper discharging operation, of a plurality of nozzles of each ink-jethead to be subject to measurement, which discharge inks in amounts asdifferent as possible under predetermined conditions are obtained inadvance by a gravimetric method or an absorbance method.

In this embodiment, the amounts of ink discharged from four nozzles, perdischarging operation, which exhibited different discharging amountsunder the predetermined conditions were obtained in advance by thegravimetric method.

Subsequently, inks are discharged from the four nozzles, whosedischarging amounts per discharging operation have been obtained in thismanner, under the same conditions as those set when the dischargingamounts have been obtained. The densities of the ink dots formed on theglass substrate 302 by these inks are measured. With this measurement,the amounts of ink discharged from the four nozzles and the densities ofthe ink dots formed by the inks are obtained in one-to-onecorrespondence. Note that the density data of the ink dots formed by thefour nozzles were obtained by sampling 50 printed dots and calculatingthe average values of the sampled values. In this case, the standarddeviations of the density data were within 5% with respect to theaverage values.

FIG. 24 is a graph showing the relationship between the amounts of inkdischarged from the four nozzles per discharging operation and thedensities of the ink dots formed on the glass substrate 302 by the inks.Referring to FIG. 24, the bullets are points indicating the amounts ofink discharged from the four nozzles and the densities of the ink dots.As is obvious from this graph, the four points are present almost on astraight line. If, therefore, a straight line passing through the fourpoints is drawn, the density of an ink dot corresponding to an arbitrarydischarging amount as a point on this straight line can be uniquelyobtained. This straight line will be referred to as a calibration curve.

This calibration curve is expressed by a straight line. A calibrationcurve can therefore be obtained by plotting at least two points on agraph. That is, a calibration curve can be obtained by using at leasttwo nozzles instead of using the four nozzles as in the above case. Inthis embodiment, however, since ink discharging amount data obtained bythe gravimetric method or the absorbance method is used to obtain acalibration curve, the precision of each measuring method directlyaffects the precision of discharging amount measurement in thisembodiment. For this reason, a calibration curve is preferably obtainedby using three or more nozzles. In addition, as is obvious, a newcalibration curve must be obtained every time an ink to be used ischanged.

Subsequently, on the basis of the density of a line pattern, which hasalready been obtained, and the above calibration curve, the amount ofink discharged from one nozzle, per discharging operation, whichcorresponds to the density of the line pattern is obtained. The inkdischarging amount to be obtained in this step is the amount of inkdischarged from one nozzle per discharging operation, but is not theamount of a plurality of inks like those forming a line pattern.However, the present inventors have experimentally confirmed that theamount of ink discharged per discharging operation can be obtained byusing the density of a line pattern with little influence on theprecision in measuring the discharging amount.

In the above manner, the amount of ink discharged from each nozzle ofeach of the heads 204 a, 204 b, and 204 c per discharging operation isobtained, and variations in the amounts of ink discharged from therespective nozzles can be measured.

If there are density differences between the respective line patterns,the above shading correction is performed in step S7 in FIG. 20 tochange the ink discharging densities in units of nozzles, therebyeliminating the density irregularity. Data indicating how to change thedensities of inks discharged from the respective nozzles is generated onthe basis of the variations in the amounts of ink discharged from therespective nozzles. These ink discharging densities are determined suchthat the total amounts of inks landing per unit length in the scanningdirection (X direction) become uniform for the respective nozzles.Consider a nozzle whose discharging amount per discharging operation issmall. In this case, the ink discharging density in the scanningdirection is increased. As to a nozzle whose discharging amount perdischarging operation is larger, the ink discharging density in thescanning direction is decreased. Shading correction is performed on thebasis of the data obtained in this manner, and line patterns like thosein FIG. 23 are printed on the glass substrate 302. The densities of theline patterns are detected again by the line sensor camera 310.

If further correction based on these detected densities is required, bitcorrection is performed.

FIG. 25 is a flow chart showing the detailed contents of the procedurefor measuring bit correction information (step S8) in the flow chart ofFIG. 20.

In this embodiment, to perform bit correction, the width of a preheatpulse is changed in 16 levels (bit correction values “0” to “15”). Thisbit correction information is measured to obtain information indicatinghow the amount of ink discharged from each nozzle changes when the widthof a preheat pulse is changed by one level of the 16 levels.

The line patterns shown in FIG. 23 have already been printed with bitcorrection value “8” in step S6. In this case, therefore, in step S15,the line patterns shown in FIG. 23 are printed while the width of eachpreheat pulse is minimized (bit correction value “0”).

Subsequently, the line patterns shown in FIG. 23 are printed again whilethe width of each preheat pulse is increased to the 16th level, i.e., tothe maximum length (bit correction value “15”) (step S16). As a linepattern is printed while the bit correction value is increased in thismanner, the amount of ink discharged increases. The density of the linepattern therefore gradually increases.

The line sensor camera 310 is scanned over the glass substrate 302 toread the density of the line pattern with bit correction value “0”, thedensity of the line pattern with bit correction value “8”, and thedensity of the line pattern with the bit correction value “15” (stepS17). The amounts of ink discharged from each nozzle with bit correctionvalues “0”, “8”, and “15” are obtained from these pieces of densityinformation on the basis of the above calibration curve.

With this operation, information indicating how the amount of inkdischarged from each nozzle changes as the bit correction value ischanged in levels, i.e., at three points corresponding to bit correctionvalues “0”, “8”, and “15”, is obtained. A curve passing through thesethree points is obtained by the least squares method in units ofnozzles. On the basis of the curve obtained in this manner, a change inthe amount of ink discharged from each nozzle with a change in bitcorrection value by one level can be obtained (step S18). That is, thiscurve shows the specific bit correction values (levels) for therespective nozzles, i.e., the specific widths of preheat pulses, withwhich the amounts of ink discharged from the respective nozzles are madeequal.

In step S9 in FIG. 20, shading correction is performed on the basis ofthe obtained data, and bit correction is performed on the basis of thedata about the above bit correction, thereby printing the line patternsshown in FIG. 23 again. The densities of these line patterns aremeasured by the line sensor camera 310 again. At this stage, thedensities of the respective line patterns should be made almost equal.

When a multi-pass print operation is to be performed to eliminate randomvariations in the amounts of ink discharged after shading correction orboth shading correction and bit correction, the nozzle used to color onepixel array in the scanning direction is changed in each scanningoperation (one pass) in the above multi-pass printing operation. In stepS10 in FIG. 20, data indicating a combination of nozzles, i.e., thespecific ordinal numbers of nozzles to be used in the respectivescanning operations, is generated. In generating this data, since thedata about the amount of ink discharged from each nozzle after bitcorrection has already been obtained, a simulation for calculating inkdischarging amounts is performed by using a computer in correspondencewith all the combinations of nozzles, i.e., the first nozzle in thefirst pass and the second nozzle in the second pass; the first nozzle inthe first pass and the third nozzle in the second pass; . . . , thefirst nozzle in the first pass and the nth nozzle in the second pass;the second nozzle in the first pass and the third nozzle in the secondpass; the second nozzle in the first pass and the fourth nozzle in thesecond pass; . . . , and the second nozzle in the first pass and the nthnozzle in the second pass. Of these combinations, a combination withwhich the irregularity in total amount of ink discharged per unit lengthin the scanning direction for each pixel array is minimized is selected.Similarly, the above simulation calculation is performed to obtain dataindicating the specific number of passes to be performed to color onepixel array so as to minimize the irregularity in total amount of inkdischarged. In a multi-pass operation, however, a considerable effectcan be expected even if the use of every nth nozzle and the execution ofm passes are uniformly set. In this case, therefore, these settings maybe fixed.

In step S11 in FIG. 20, data about an ink discharging method and nozzlesto be used for the mass production of color filters is generated on thebasis of the data obtained in steps S7, S9, and S10.

The mass production data obtained by the adjusting device 300 of thehead unit 55 in this manner is sent to the color filter manufacturingapparatus 90. In addition, the head unit 55, whose inclination angle inthe scanning operation and relative position have been adjusted by theadjusting device 300, is mounted on the manufacturing apparatus 90, andonly pivot angle adjustment within a horizontal plane is performed.Thereafter, coloring of a color filter is actually performed.

A method of eliminating irregularity in coloring a color filter by usingthe head unit 55 having undergone adjustment in the above manner will bedescribed next.

Prior to a description of the irregularity eliminating method of thisembodiment, an existing method of coloring a color filter by themulti-pass method will be described first.

Consider a case in which a color filter is colored in three passes, witheach nozzle to be used being shifted one by one in each pass. Considerone pixel array G1 of the color filter, and three adjacent nozzles N1,N2, and N3 to be used to color this pixel array. Assume that the amountsof ink discharged from these nozzles vary, i.e., the amount of inkdischarged from the nozzle N1 per discharging operation is 10 ng(nanogram), the amount of ink discharged from the nozzle N2 perdischarging operation is 20 ng, and the amount of ink discharged fromthe nozzle N3 per discharging operation is 40 ng.

The pixel array G1 is colored in one pass by using these nozzles. Assumethat the length of the pixel array G1 is about 200 mm, and an ink mustbe discharged from the nozzle N1 2,000 times to color the pixel arrayG1. In this case, the total amount of ink required to color the pixelarray G1 is 10 (ng)×2000=20000 ng. In general, in performing shadingcorrection, ink discharging densities are set to equalize the totalamounts of ink discharged from the respective nozzles to color one pixelarray. For this reason, when the same pixel array G1 is to be colored byusing the nozzle N2, an ink must be discharged 20000 (ng)÷20 (ng)=1000times. In this case, the intervals at which an ink is discharged fromthe nozzle N1 to color the pixel array G1 are 200 (mm)÷2000 (times)=100μm. When coloring is performed by using the nozzle N2, since the numberof times an ink is discharged to color one pixel is ½ that in the caseof the nozzle N1, the ink discharging intervals are 200 μm. Similarly,when the nozzle N3 is to be used, the number of times an ink isdischarged is 20000 ng÷40 ng=500, and the ink discharging intervals are400 μm.

In other words, when one pixel array is to be colored in one pass byusing the above three nozzles with different discharging amounts, a10-ng ink is discharged from the nozzle N1 2,000 times at 100-μmintervals; a 20-ng ink is discharged from the nozzle N2 1,000 times at200-μm intervals; and a 40-ng ink is discharged from the nozzle N3 500times at 400-μm intervals.

Consider a case in which one pixel array G1 is colored in three passesby using these three nozzles while the nozzle used in one pass ischanged to another nozzle in another pass. In this case, an ink isgenerally discharged from each of the three nozzles in an amount ⅓ thetotal amount of ink required for coloring. According to this method,therefore, an ink is discharged from the nozzle N1 2000 (times)/3=667times in the first pass. To equally distribute the ink discharged 667times in the scanning direction of the pixel array G1, a 10-ng ink mustbe discharged at intervals of 300 μm, i.e., three times larger than 100μm. Similarly, in the second pass, an ink is discharged 1000(times)/3=333 times. That is, a 20-ng ink is discharged at intervals of600 μm. In addition, an ink is discharged from the nozzle N3 500(times)/3=167 times. That is, a 40-ng ink is discharged at intervals of1,200 μm.

The intervals at which inks are discharged from the respective nozzlesare determined in this manner. According to an existing method, inks aredischarged from the respective nozzles from the same position, and eachpixel array is colored in three passes. If, however, the dischargingstart positions in the three passes are the same, a 10-ng ink, a 20-ngink, and a 40-ng ink overlap at the ink discharging start position andpositions set at 1,200-μm intervals from the start position; a 10-ng inkand a 20-ng ink overlap at positions set at 600-μm intervals from thestart position; and only a 10-ng ink is discharged at the remainingpositions, as shown in FIG. 26. For this reason, as shown in FIG. 27, atthe positions where the inks overlap, the landing inks spread wide onthe glass substrate. However, at the positions where the inks do notoverlap, the landing inks do not spread much on the glass substrate. Asa result, color irregularity occurs in the pixels. Even if thedischarging start positions in the respective passes are shifted fromeach other to solve this problem, since points corresponding to integermultiples of the intervals at which an ink is discharged in the firstpass (=integer multiples of the intervals at which an ink is dischargedin the nth pass+the amount of a shift from the start position) appear,overlapping of inks cannot be avoided. That is, this method does notprovide a perfect solution to the above problem.

In this embodiment, therefore, the above problem is solved by thefollowing method.

The total number of times inks must be discharged to color one pixelarray in three passes is the sum of 667 for the nozzle N1, 333 for thenozzle N2, and 167 for the nozzle N3, i.e., 667+333+167=1167. In thisembodiment, 1,167, the total number of times inks are discharged, issimply divided by three; the numbers of times inks are discharged fromthe nozzles N1, N2, and N3 are uniformly set to 1167÷3=389. In addition,the intervals at which the inks are discharged from the respectivenozzles are uniformly set to the value obtained by dividing the length(200 mm) of the pixel array by 1,167, i.e., 200 (mm)÷1167=171 μm.

More specifically, as shown in FIG. 28, first of all, a 10-ng ink isdischarged from the nozzle N1 at the discharging start position.Thereafter, a 10-ng ink is sequentially discharged from the nozzle N1 atintervals of 513 μm, which is three times larger than 171 μm.Discharging of the ink from the nozzle N2 is started at a positionshifted from the discharging start position by 171 μm, and a 20-ng inkis discharged at 513-μm intervals. Discharging of the ink from thenozzle N3 is started at a position shifted from the discharging startposition by 342 μm, and a 40-ng ink is discharged at 513-μm intervals.With this operation, all the 10-ng ink from the nozzle N1, the 20-ng inkfrom the nozzle N2, and the 40-ng ink from the nozzle N3 are arranged onthe pixel array at equal intervals of 171 μm; no inks land in anoverlapping state. With this operation, the color irregularity shown inFIGS. 26 and 27 is reduced, and a color filter with higher quality canbe manufactured.

According to the above description, the numbers of times inks aredischarged to color one pixel array, which should be 667 for the nozzleN1, 333 for the nozzle N2, and 167 for the nozzle N3, are uniformly setto 389. That is, the total amount of ink discharged to color one pixelarray differs from that required essentially. More specifically, thetotal amount of ink required essentially is 10 (ng)×667+20 (ng)×333+40(ng)×167=19890 ng, whereas the total amount of ink in this embodiment is10 (ng)×389+20 (ng)×389+40 (ng)×389=27230 ng. In the embodiment,however, variations in the amounts of ink discharged from the respectivenozzles are set to 10 ng, 20 ng, and 40 ng, i.e., greatly differentvalues. In practice, variations in amounts of ink discharged after bitcorrection are about ±5% at most. If, for example, the amount of inkdischarged from the first nozzle is 10 ng, the amount of ink dischargedfrom the second nozzle is 9.5 ng, and the amount of ink discharged fromthe third nozzle is 10.5 ng. Even if, therefore, the numbers of timesinks are discharged from the respective nozzles are made uniform, littleinfluence is exerted on the total amount of ink discharged to color onepixel array. With the use of the method of this embodiment, therefore,any inconvenience, e.g., an ink overflow due to different total amountsof ink discharged, does not occur, but only the effect of reducing colorirregularity can be obtained.

FIG. 29 shows the concept of the color filter coloring method accordingto this embodiment. As shown in FIG. 29, inks are discharged at equalintervals to color pixel arrays while the nozzles to be used are shiftedin the first, second, and third passes. In practice, adjacent pixelarrays are colored in different colors, R, G, and B. In FIG. 29, for thesake of descriptive convenience, however, the pixel arrays are coloredin the same color. In addition, the differences between the amounts ofink discharged are indicated by the nozzles with different diameters.

FIG. 30 is a view showing a method of verifying whether a manufacturedcolor filter has been manufactured by the method of the presentinvention.

Assume that a given pixel of a manufactured color filter is colored inthe manner indicated on the left end of FIG. 30, and a print mark uniqueto an ink-jet system is confirmed, as indicated by the central portionof FIG. 30. In this case, virtual circles of the respective ink dots aredrawn on the basis of the shapes of the overlapping portions of theprinted ink dots. If the virtual centers of gravity are located at anequal pitch, it can be verified that this color filter has beenmanufactured by the method of the present invention.

Various changes and modifications of the above embodiments can be madewithout departing the spirit and scope of the invention.

For example, in the above embodiment, a color filter is colored in threepasses. However, the number of passes is to be determined by theabove-described simulation in the embodiment, but is not limited tothree.

As methods of adjusting the amounts of ink discharged, two types ofmethods, i.e., shading correction and bit correction, are described.However, it suffices if one of the methods is performed. In many cases,the amounts of ink discharged can be satisfactorily corrected by shadingcorrection alone. That is, bit correction is not essential.

According to the above description, when inks are to be discharged atequal intervals, the discharging intervals are set in accordance withthe distance obtained by dividing the length of each pixel array in thescanning direction by the total number of inks discharged in a pluralityof scanning operations. When, however, inks are to be finally dischargeddiscretely, if the absolute value of (Pn)−(Pn −1) (i.e., variations indischarging intervals)≦Pb (where Pb is the resolution of dischargingintervals, and Pn is the intervals at which inks are discharged), theintervals can be regarded as equal intervals in the present invention.

Furthermore, when heads whose discharging amounts are uniformlycompensated are to be used, the adjusting device may be used only forpositioning.

According to the above description, the present invention is applied tothe print apparatus of the system, among various ink-jet print systems,which has a means (e.g., an electrothermal converter or laser light) forgenerating heat energy as energy used to discharge an ink, and changesthe state of an ink by using the heat energy. According to this system,a high-density, high-definition print operation can be realized.

As for the typical structure and principle, it is preferable that thebasic structure disclosed in, for example, U.S. Pat. Nos. 4,723,129 or4,740,796 is employed. The above method can be adapted to both aso-called on-demand type apparatus and a continuous type apparatus. Inparticular, a satisfactory effect can be obtained when the on-demandtype apparatus is employed because of the structure arranged in such amanner that one or more drive signals, which rapidly raise thetemperature of an electrothermal converter disposed to face a sheet or afluid passage which holds the fluid (ink) to a level higher than levelsat which film boiling takes place, are applied to the electrothermalconverter in accordance with print information so as to generate heatenergy in the electrothermal converter and to cause the heat effectingsurface of the print head to generate film boiling so that bubbles canbe formed in the fluid (ink) to correspond to the one or more drivesignals. The enlargement/contraction of the bubble will cause the fluid(ink) to be discharged through a discharging opening so that one or moreinks are formed. If a pulse shape drive signal is employed, the bubblecan be enlarged/contracted immediately and properly, causing a furtherpreferred effect to be obtained because the fluid (ink) can bedischarged while revealing excellent responsiveness.

It is preferable that a pulse drive signal disclosed in U.S. Pat. Nos.4,463,359 or 4,345,262 is employed. If conditions disclosed in U.S. Pat.No. 4,313,124 which is an invention relating to the temperature risingratio at the heat effecting surface are employed, a satisfactory printresult can be obtained.

As an alternative to the structure (linear fluid passage orperpendicular fluid passage) of the print head disclosed in each of theabove inventions and having an arrangement that discharge ports, fluidpassages and electrothermal converters are combined, a structure havingan arrangement that the heat effecting surface is disposed in a bentregion and disclosed in U.S. Pat. Nos. 4,558,333 or 4,459,600 may beemployed. In addition, the following structures may be employed: astructure having an arrangement that a common slit is formed to serve asa discharge section of a plurality of electrothermal converters anddisclosed in Japanese Patent Laid-Open No. 59-123670; and a structuredisclosed in Japanese Patent Laid-Open No. 59-138461 in which an openingfor absorbing pressure waves of heat energy is disposed to correspond tothe discharge section.

Furthermore, as a print head of the full line type having a lengthcorresponding to the maximum width of a recording medium which can beprinted by the print apparatus, either the construction which satisfiesits length by a combination of a plurality of print heads as disclosedin the above specifications or the construction as a single full linetype print head which has integrally been formed can be used.

In addition, the invention is effective for a print head of the freelyexchangeable chip type which enables electrical connection to the printapparatus main body or supply of ink from the main device by beingmounted onto the apparatus main body, or for the case by use of a printhead of the cartridge type provided integrally on the print head itself.

It is preferred to additionally employ the print head restoring meansand the auxiliary means provided as components of the present inventionbecause the effect of the present invention can be further stabilizedthereby. Specifically, it is preferable to employ a print head cappingmeans, a cleaning means, a pressurizing or suction means, anelectrothermal converter, another heating element or a preheating meansconstituted by combining them and a pre-discharging mode in which adischarging operation is performed independently from the printoperation in order to stably perform the print operation.

Although a fluid ink is employed in the above embodiments of the presentinvention, an ink which solidifies at the room temperature or lower, oran ink which softens or liquifies at the room temperature may be used.That is, any ink which liquifies when a print signal is supplied may beused.

Furthermore, an ink which is solidified when it is caused to stand, andliquified when heat energy is supplied in accordance with a print signalcan be adapted to the present invention to positively prevent atemperature rise caused by heat energy by utilizing the temperature riseas energy of state transition from the solid state to the liquid stateor to prevent ink evaporation. In any case, an ink which is liquifiedwhen heat energy is supplied in accordance with a print signal so as tobe discharged in the form of fluid ink, or an ink which is liquifiedonly after heat energy is supplied, e.g., an ink which starts tosolidify when it reaches a recording medium, can be adapted to thepresent invention. In the above case, the ink may be of a type which isheld as fluid or solid material in a recess of a porous sheet or athrough hole at a position to face the electrothermal converter asdisclosed in Japanese Patent Laid-Open No. 54-56847 or Japanese PatentLaid-Open No. 60-71260. It is the most preferred way for the ink to beadapted to the above film boiling method.

As has been described above, according to the present invention, sinceall the intervals at which inks are discharged in a plurality ofscanning direction are made equal, concentration of inks on one portionin each pixel array can be prevented. A color filter with little colorirregularity can therefore be manufactured.

The present invention is not limited to the above embodiments andvarious changes and modifications can be made within the spirit andscope of the present invention. Therefore, to apprise the public of thescope of the present invention the following claims are made.

What is claimed is:
 1. A method of manufacturing a color filter bycoloring each of a plurality of filtering portion arrays, each filteringportion array including a plurality of filtering portions arranged onone line extending in a predetermined direction, using a plurality ofinks discharged from a plurality of different ink discharge nozzles, bydischarging inks from the plurality of different ink discharge nozzlesto a substrate with the plurality of filtering portion arrays, saidmethod comprising the steps of: determining discharge intervals betweenthe plurality of inks discharged from the plurality of different inkdischarge nozzles to one filtering portion array based on amounts of theplurality of inks discharged from the plurality of different inkdischarge nozzles to color the one filtering portion array; and coloringthe one filtering portion array by discharging the plurality of inksfrom the plurality of different ink discharge nozzles based on thedischarge intervals between the plurality of inks determined in saiddetermining step, wherein, in said determining step, one value isassigned to the discharge intervals between the plurality of inksdischarged from the plurality of different ink discharge nozzles usedfor coloring the one filtering portion array so that each of thedischarge intervals between the plurality of inks is substantiallyequal, and the one value varies in accordance with a total amount of theplurality of inks discharged onto the one filtering portion array fromthe plurality of different ink discharge nozzles, and wherein, in saidcoloring step, the plurality of inks are discharged from the pluralityof ink discharge nozzles in such a manner that all of the plurality ofinks land on the one filtering portion array at positions that arespaced apart from one another by equal intervals.
 2. A method ofmanufacturing a color filter according to claim 1, wherein adjacent inksof the plurality of inks discharged to the one filtering portion arraypartially overlap each other and the one filtering portion array isfilled overall with the plurality of inks.
 3. A method of manufacturinga color filter according to claim 1, wherein the plurality of inks aredischarged from the plurality of ink discharge nozzles by relativescanning operations of the plurality of ink discharge nozzles and thesubstrate.
 4. The method of manufacturing a color filter according toclaim 1, wherein the inks are discharged by generating heat energy andapplying the heat energy to the inks.
 5. An apparatus for manufacturinga color filter by coloring each of a plurality of filtering portionarrays, each filtering portion array including a plurality of filteringportions arranged on one line extending in a predetermined direction,using a plurality of inks discharged from a plurality of different inkdischarge nozzles, by discharging inks from the plurality of differentink discharge nozzles to a substrate with the plurality of filteringportion arrays, said apparatus comprising: an ink-jet head with theplurality of ink discharge nozzles; determining means for determiningdischarge intervals between the plurality of inks discharged from theplurality of different ink discharge nozzles to one filtering portionarray based on amounts of the plurality of inks discharged from theplurality of different ink discharge nozzles to color the one filteringportion array; and control means for controlling said ink-jet head toperform a coloring operation for coloring the one filtering portionarray by discharging the plurality of inks from the plurality ofdifferent ink discharge nozzles based on the discharge intervals betweenthe plurality of inks determined by said determining means, wherein saiddetermining means assigns one value to the discharge intervals betweenthe plurality of inks discharged from the plurality of different inkdischarge nozzles used for coloring the one filtering portion array sothat each of the discharge intervals between the plurality of inks issubstantially equal, and the one value varies in accordance with a totalamount of the plurality of inks discharged onto the one filteringportion array from the plurality of different ink discharge nozzles, andwherein said control means controls said ink-jet head to discharge theplurality of inks from the plurality of ink discharge nozzles in such amanner that all of the plurality of inks land on the one filteringportion array at positions that are spaced apart from one another byequal intervals.
 6. An apparatus for manufacturing a color filteraccording to claim 5, wherein adjacent inks of the plurality of inksdischarged to the one filtering portion array partially overlap eachother and the one filtering portion array is filled overall with theplurality of inks.
 7. An apparatus for manufacturing a color filteraccording to claim 5, wherein the plurality of inks are discharged fromthe plurality of ink discharge nozzles by relative scanning operationsof the plurality of ink discharge nozzles and the substrate.
 8. Theapparatus for manufacturing a color filter according to claim 5, whereinsaid ink-jet head is a head for discharging an ink by using heat energy,with the head including a heat energy generator for generating heatenergy, which is applied to the ink.
 9. A method of manufacturing acolor filter by coloring each of a plurality of filtering portions usinga plurality of inks discharged from a plurality of different inkdischarge nozzles, by discharging inks from the plurality of differentink discharge nozzles to a substrate with the plurality of filteringportions, said method comprising the steps of: determining dischargeintervals between the plurality of inks discharged from the plurality ofdifferent ink discharge nozzles to one filtering portion based onamounts of the plurality of inks discharged from the plurality ofdifferent ink discharge nozzles to color the one filtering portion; andcoloring the one filtering portion by discharging the plurality of inksfrom the plurality of different ink discharge nozzles based on thedischarge intervals between the plurality of inks determined in saiddetermining step, wherein, in said determining step, one value isassigned to the discharge intervals between the plurality of inksdischarged from the plurality of different ink discharge nozzles usedfor coloring the one filtering portion so that each of the dischargeintervals between the plurality of inks is substantially equal, and theone value varies in accordance with a total amount of the plurality ofinks discharged onto the one filtering portion from the plurality ofdifferent ink discharge nozzles, and wherein, in said coloring step, theplurality of inks are discharged from the plurality of ink dischargenozzles in such a manner that all of the plurality of inks land on theone filtering portion at positions that are spaced apart from oneanother by equal intervals.
 10. A method of manufacturing a color filteraccording to claim 9, wherein adjacent inks of the plurality of inksdischarged to the one filtering portion partially overlap each other andthe one filtering portion is filled overall with the plurality of inks.11. A method of manufacturing a color filter according to claim 9,wherein the plurality of inks are discharged from the plurality of inkdischarge nozzles by relative scanning operations of the plurality ofink discharge nozzles and the substrate.
 12. The method of manufacturinga color filter according to claim 9, wherein the inks are discharged bygenerating heat energy and applying the heat energy to the inks.
 13. Anapparatus for manufacturing a color filter by coloring each of aplurality of filtering portions using a plurality of inks dischargedfrom a plurality of different ink discharge nozzles, by discharging inksfrom the plurality of different ink discharge nozzles to a substratewith the plurality of filtering portions, said apparatus comprising: anink-jet head with the plurality of ink discharge nozzles; determiningmeans for determining discharge intervals between the plurality of inksdischarged from the plurality of different ink discharge nozzles to onefiltering portion based on amounts of the plurality of inks dischargedfrom the plurality of different ink discharge nozzles to color the onefiltering portion; and control means for controlling said ink-jet headto perform a coloring operation for coloring the one filtering portionby discharging the plurality of inks from the plurality of different inkdischarge nozzles based on the discharge intervals between the pluralityof inks determined by said determining means, wherein said determiningmeans assigns one value to the discharge intervals between the pluralityof inks discharged from the plurality of different ink discharge nozzlesused for coloring the one filtering portion so that each of thedischarge intervals between the plurality of inks is substantiallyequal, and the one value varies in accordance with a total amount of theplurality of inks discharged onto the one filtering portion from theplurality of different ink discharge nozzles, and wherein said controlmeans controls said ink-jet head to discharge the plurality of inks fromthe plurality of ink discharge nozzles in such a manner that all of theplurality of inks land on the one filtering portion at positions thatare spaced apart from one another by equal intervals.
 14. An apparatusfor manufacturing a color filter according to claim 13, wherein adjacentinks of the plurality of inks discharged to the one filtering portionpartially overlap each other and the one filtering portion is filledoverall with the plurality of inks.
 15. An apparatus for manufacturing acolor filter according to claim 13, wherein the plurality of inks aredischarged from the plurality of ink discharge nozzles by relativescanning operations of the plurality of ink discharge nozzles and thesubstrate.
 16. The apparatus for manufacturing a color filter accordingto claim 13, wherein said ink-jet head is a head for discharging an inkby using heat energy, with the head including a heat energy generatorfor generating heat energy, which is applied to the ink.